Information recording system and information recording method

ABSTRACT

System and method are devised to produce an optical recording medium suitable for identification and management. A recording layer formed in the optical recording medium is irradiated with writing light by a pickup. A visible image pattern suitable for identification, management or the like is formed on the optical recording medium by generating changes in optical characteristics of a portion irradiated with light and a portion not irradiated with light in the recording layer.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an information recording systemprovided with a function of recording visible information on an opticalrecording medium.

2. Description of the Prior Art

CDs (Compact Disk), DVDs (Digital Video Disk or Digital Versatile Disk)and so forth are known as optical recording media for opticallyrecording or reproducing information. A write-once type disk andrewritable disk in which information can be recorded have also beendeveloped, providing excellent convenience for users.

For example, a user can enjoy writing and editing contents data such asmusic, image or the like and creating his/her own disk havingoriginality by utilizing these write-once type or rewritable disks. Inaddition, a user can create discs which offer greater convenience bywriting computer program data needed for combining all their essentialapplications onto a single disc.

However, as the number of disks in use increases, a problem arises thatit is difficult to pick up a desired disk from many disks or managethese disks due to the difficulty in identifying disks from theirappearance.

Therefore, as shown in FIG. 1, a user can write characters orillustrations by using a writing tool on a side of a conventional diskwhich is not used for writing information, that is, the back side(hereinafter, referred to as label side) of a side irradiated with lightbeam for writing and reading information.

However, while the disk on which a user can write information asdescribed above can provide excellent convenience to the user, technicalbackwardness remains that the easiest way to manage disks is tohand-write characters or illustrations for identification on a labelside with a writing tool. When hand-written on a label side, thecharacters or illustrations may gradually fade away and become unclearor deteriorate appearance. Thus, development of a novel technique whichsubstitutes for handwriting and can identify a disk at one glance as inthe case of hand-written has been required.

SUMMARY OF THE INVENTION

The present invention has been accomplished to solve these conventionalproblems. Accordingly, an object of the present invention is to providean information recording system having a function of recording visibleinformation.

To achieve the above object, an aspect of the present invention is aninformation recording system and an information recording method forrecording information on an optical information recording medium,wherein a recording layer formed on the optical recording medium isirradiated with light to generate changes in optical characteristicsbetween a portion irradiated with light and an unirradiated portion inthe recording layer so that a visible image pattern is formed. Anotheraspect of the present invention is characterized in that the visibleimage pattern is formed based on a difference in reflectance between anarea where pits are formed by irradiating the recording layer formed onthe optical recording medium with light and an area which is notirradiated with light not to form pits.

According to these information recording system and informationrecording method, a recording layer which is formed in an opticalrecording medium is irradiated with light by writing means. Thisirradiated light causes changes in optical characteristics of therecording layer. A visible image pattern can be formed by forming aportion where the optical characteristics change. That is, the visibleimage pattern is formed based on the difference in reflectance betweenan area where pits are formed by irradiating the recording layer withlight and an area which is not irradiated light not to form pits. Animage pattern having an identification property similar to conventionalhand-written characters, symbols, illustrations or the like can beformed by forming this visible image pattern into an appropriate shape.Thus, management, identification and the like of a plurality of opticalrecording media become possible.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a disk on a label side of which characters or the like arehandwritten;

FIG. 2 shows an appearance of a digital audio system according to oneembodiment of the invention;

FIG. 3 is a block diagram showing an internal configuration of thedigital audio system of this embodiment;

FIG. 4 is a block diagram showing a configuration of a pit art datagenerating partXX provided in the digital audio system of thisembodiment;

FIG. 5 is a flowchart for explaining operation in a first automatic modein the digital audio system of the embodiment;

FIG. 6 is a flowchart for further explaining operation in the firstautomatic mode in the digital audio system of this embodiment;

FIG. 7 is an explanatory view showing an unrecorded area in which a pitart is recorded;

FIG. 8 is an explanatory view showing an example of a preview display ina display unit;

FIG. 9 is an explanatory view showing an example when a pit art isrecorded;

FIG. 10 is a flowchart for explaining operation in a second automaticmode in the digital audio system of this embodiment.

FIG. 11 is a flowchart for explaining operation in a manual mode in thedigital audio system of this embodiment; and

FIGS. 12 and 13 are explanatory views showing examples of a previewdisplay presented in the display unit in the manual mode.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the present invention will be described below withreference to the accompanying drawings. A digital audio system capableof using a write-once type disk such as CD-R or the like, a rewritabledisk such as CD-RW or the like and a disk exclusively for reproductionsuch as CD-ROM, CD-DA or the like is described as a preferredembodiment.

First, terms “pit art”, “pit art data” and “pit art recording” used indescription of this embodiment are defined.

“Pit art” is an image pattern which is made visible by recording data ina recording layer of a disk such as a CD-R or the like in which data canbe written and utilizing the difference in reflectance or the likebetween a portion where data is recorded and a portion where data is notrecorded. That is, unlike ordinary data recording, “pit art” is an imagepattern such as characters, illustrations or the like recorded in arecording layer so as to be visible.

“Pit art data” is data written to form a “pit art” in a recording layerof a disk.

“Pit art recording” is to record “pit art data” in a recording layer ofa disk, in which data can be written.

FIG. 2 shows an appearance of this digital audio system. FIGS. 3 and 4are block diagrams showing an internal configuration of this digitalaudio system.

In FIG. 2, a front panel 2 of this digital audio system 1 is providedwith a disk inserting port 3 for loading and unloading a disk, which isan optical recording medium, and a display unit 4 formed with a liquidcrystal display or the like. A plurality of operating switches areprovided surrounding the disk inserting port 3 and the display unit 4.

As representative operating switches, an eject switch 5 for allowing theloading and unloading, a power-on switch 6, a rotary switch 7 forcontrolling the sound volume, a plurality of function switches 8disposed to the right side of the display unit 4, a plurality offunction switches 9 disposed to the left side of the display unit 4, arecording start switch 10 for instructing the start of recording and arotary switch 11 called jog dial are provided.

A movable tray (not shown) for placing a disk thereon is provided in thedisk inserting port 3. When the eject switch 5 is pressed, the movabletray is moved back and forth via the disk inserting port 3 so as to loador unload a disk to or from a so-called clamp position.

More specifically, when the eject switch 5 is pressed in a state thatthe movable tray is positioned deep inside the disk inserting port 3,the movable tray is projected forward via the disk inserting port 3.Consequently, a disk already loaded can be removed or a new disk can beloaded. When the eject switch 5 is pressed in a state that the movabletray is projected forward via the disk inserting port 3, the movabletray is automatically moved deep into the disk inserting port 3 andloading is carried out.

In this digital audio system 1, a disk is placed with its label sidefacing the movable tray. Consequently, a user loads a disk onto orunloads from the movable tray while directing the label side of the diskdownward (the movable tray side) with the side of the disk on which datais recorded or reproduced in view.

The plurality of function switches 8 are constituted by a plurality ofoperating switches for starting reproduction of data recorded in a disk,temporarily stopping data reproduction, specifying a track number withwhich data is recorded and so forth.

The plurality of function switches 9 are constituted by a plurality ofoperating switches operated when pit art data is written in a write-oncetype disk or a rewritable disk. More specifically, in addition to a pitart recording start switch for instructing the start of pit artrecording, the function switches 9 are constituted by a plurality ofediting switches for editing size, arrangement or the like ofcharacters, illustrations or the like to be recorded as a pit art and asettlement switch for settling the edited characters, illustrations orthe like.

The rotary switch 11 called as a jog dial is provided for selectingcharacters, symbols, illustrations or the like to be recorded as a pitart by a user. Each time the user rotates the rotary switch 11 at aprescribed angle, data of the characters, symbols, illustrations or thelike is switched. When the settlement switch is operated, thecharacters, symbols, illustrations or the like selected by the rotaryswitch 11 are settled as a pit art.

While not shown in FIG. 2, external equipment connecting terminals forconnecting external equipment such as a CS tuner, BS tuner, CD player,MD player, DVD player or the like and a keyboard connecting terminal forconnecting a keyboard are provided on the rear surface of the digitalaudio system 1.

The internal configuration of this digital audio system 1 will bedescribed below with reference to FIG. 3. A digital input terminal 13connected to a digital input circuit 12, an analog input terminal 15connected to an A/D converter 14, a digital output terminal 17 connectedto a digital output circuit 16 and an analog output terminal 19connected to a D/A converter 18 are provided as the external equipmentconnecting terminals.

The digital input terminal 13 is composed of an optical digital inputterminal or coaxial digital input terminal. The digital input circuit 12converts optical or electrical digital data supplied via the digitalinput terminal 13 to digital data which can be processed by signals andinputs the data.

Consequently, when external equipment such as a CS tuner, BS tuner, CDplayer, MD player or the like is connected to the digital input terminal13, digital data supplied from this external equipment is inputted inthis digital audio system 1 as digital data.

The analog input terminal 15 is provided for inputting analog signals.That is, when external equipment such as a CD player, MD player or thelike is connected to the analog input terminal 15 and audio signalsreproduced as analog data are supplied from this external equipment, theaudio signals are converted to digital data by the A/D converter 14 andinputted into the digital audio system 1.

The digital output terminal 17 is composed of an optical digital outputterminal or coaxial digital output terminal. When the digital audiosystem 1 reproduces data in a write-once type disk, rewritable disk ordisk exclusively used for reproduction, the digital output circuit 16converts the reproduced digital data obtained by this reproduction tooptical or electrical digital data and outputs the data to externalequipment via the digital output terminal 17.

The D/A converter 18 converts digital data reproduced from a write-oncetype disk, rewritable disk or disk exclusively used for reproduction toanalog signals and outputs the signals to the outside via the analogoutput terminal 19. Consequently, when an analog amplifier connected toa speaker is connected to the analog output terminal 19, reproducedsound can be played by the speaker. When analog equipment such as ananalog tape recorder or the like is connected, reproduced sound can berecorded in the analog form.

The keyboard connecting terminal 20 is connected to a system controller21 provided with a microprocessor (MPU). When a user connects a keyboard22 conforming to the JIS or the like to the keyboard connecting terminal20, instruction for pit art data editing and pit art recording can becarried out by keyboard operation instead of operating the functionswitches 9 and the rotary switch 11.

An encoder 26 and an LD drive circuit are subordinately connected to thedigital input circuit 12 and A/D converter 14 via a two-contactsswitching circuit 23 controlled by the system controller 21.

The encoder 26 is controlled by the system controller 21 and performsEFM (Eight-Fourteen Modulation) and CIRC (Cross Interleave Reed-SolomonCode) interleaving on data D1 inputted from the two-contacts switchingcircuit 23. The data D2 for writing generated during this processing isoutputted to the LD drive circuit 27. Although details will be describedlater, when pit art data Dp is supplied from the system controller 21,the data D2 for writing is generated based on the pit art data Dp andoutputted to the LD drive circuit 27.

The LD drive circuit 27 is controlled by the system controller 21 andperforms power amplification of data D2 for writing from the encoder 26and supplies the data to a semiconductor laser (not shown) in a pickup28. Consequently, a recording layer of a disk DSC is irradiated withlight modulated by the power amplified data D3 for writing (hereinafter,referred to as writing light) to perform data writing.

When data is read from the disk DSC, the LD drive circuit 27 irradiatesthe recording layer of the disk DSC with light having a certain power(hereinafter, referred to as reading light) by supplying a certain powerinstructed by the system controller 21 to the semiconductor laser in thepickup 28.

A spindle motor 29 for rotating a clamped disk DSC at a certain linearvelocity and a feeding motor 30 for moving the pickup 28 back and forthin the radius direction of the disk DSC are provided at theaforementioned clamp position.

Furthermore, an optical detector (not shown) in the pickup 28 performsphotoelectric conversion of returning light generated in response to thewriting light or reading light irradiated on the disk DSC when data iswritten or read. An RF amplifier 31 supplies the photoelectricallyconverted signals SRF to an address decoder 32, servo control circuit 33and decoder 34.

The address decoder 32 detects a track address on the disk DSCirradiated with the writing light or reading light from thephotoelectrically converted signals SRF outputted from the RF amplifier31 and supplies the detected address data D4 to the encoder 26 and thesystem controller 21.

Consequently, the encoder 26 transfers the data D2 for writing insynchronism with the address data D4 to the LD drive circuit 27 when thedata is recorded as described above. The system controller 21 judgeswhether the pickup 28 is in an on-track state at the track address onthe disk DSC where data is to be written when the data is recorded.

The decoder 34 receives input of the photoelectrically converted signalsSRF outputted from the RF amplifier 31 and the address data D4 outputtedfrom the address decoder 32, and EFM demodulates and deinterleaves audiodata or the like included in the photoelectrically converted signals SRFin synchronism with the address data D4. Consequently, decodingprocessing opposite to processing by the encoder 26 is performed anddecoded data D4 generated by this processing is supplied to the digitaloutput circuit 16 and the D/A converter 18.

When TOC (table of contents) data is read from a disk DSC by datareproduction, the decoder 34 decodes this TOC data and supplies thedecoded TOC data Dt2 to the system controller 21.

The servo control circuit 33 detects tracking error or focusing errorbased on the photoelectrically converted signals SRF outputted from theRF amplifier 31 and servo-controls the spindle motor 29, feeding motor30 and pickup 28 based on the detection result.

Furthermore, a pit art data memory 37 and a standard data memory 38 areconnected to the system controller 21 and a pit art data generatingpartXX 39 shown in FIG. 4 is provided.

The pit art data generating partXX 39 is constituted by a character datadecoding partXX 40, pit art data editing partXX 41 and addressgenerating partXX 42 and generates pit art data Dp under the control ofthe microprocessor MPU provided in the system controller 21.

The character data decoding partXX 40 receives input of the characterinformation data from the rotary switch 11 called jog dial and characterinformation data from the keyboard 22 via the microprocessor MPU,retrieves standard character data Dc stored in the standard data memory38 in advance based on the character information data D6 and suppliesthe data to the pit art data editing partXX 41.

Although details will be described later, when data in an informationrecording medium such as a CD, MD or the like in which data is alreadyrecorded is reproduced and a pit art is recorded based on the reproduceddata, the character data decoding partXX 40 receives input of thecharacter information data such as TOC, UTOC (user table of contents) orthe like included in the reproduced data and supplies the data to thepit art data editing partXX 41.

When a pit art is recorded based on data supplied from externalequipment such as a CS tuner, BS tuner or the like, the character datadecoding partXX 40 receives input of the character information data Dpincluded in the data and supplies the data to the pit art data editingpartXX 41.

The pit art data editing partXX 41 converts standard character data Dcto data Dbmp in a bit map format (hereinafter, referred to as bit mapdata) and stores the data in the pit art data memory 37. When the useredits data by operating the function switches 9 or the keyboard 22, thepit art data editing partXX 41 receives input of the editing instructiondata D7 via the microprocessor MPU, edits the bit map data Dbmpaccording to the editing instruction and stores the data in the pit artdata memory 37.

The address generating partXX 42 generates address data Dr for readingbit map data Dbmp stored in the pit art data memory 37. That is, thispartXX judges the position of the pickup 28 in relation to the disk DSCbased on the address data D4 supplied from the address decoder 32 viathe microprocessor MPU. Then, when the partXX determines that the pickup28 comes to the position at which a pit art is to be recorded, thepartXX accesses the pit art data memory 37 by the address data Dr andsupplies the bit map data Dbmp as pit art data Dp for each dot to theencoder 26 via the microprocessor MPU and allows the pickup 28 to recordthe pit art.

Operation of this digital audio system 1 having the above constitutionwill be described below.

This digital audio system 1 is provided with three kinds of modes forrecording a pit art under the control of the system controller 21.

When a user selects a first mode (hereinafter, external data recordingmode) by a function switch 9 and audio data supplied from externalequipment such as a CS tuner, BS tuner, CD player, MD player, DVD playeror the like connected to the digital input terminal 13 is recorded(copied) in a write-once type disk or a rewritable disk, characterinformation data supplied from a CS tuner or BS tuner, characterinformation data included in TOC data supplied from a CD player orcharacter information data included in UTOC data supplied from an MDplayer are automatically edited. Then, pit art data Dp generated byautomatic editing is written in the write-once type disk or rewritabledisk. Thus, a pit art is recorded automatically.

When the user selects a second mode (hereinafter, referred to asinternal data recording mode) by a function switch 9, the TOC dataalready stored in a write-once type disk or rewritable disk loaded inthe digital audio system 1 is reproduced. Character information dataincluded in the reproduced TOC data is automatically edited and the pitart data Dp generated by automatic editing is written in the loadedwrite-once type disk or rewritable disk. Thus, a pit art is recordedautomatically.

When the user selects a third mode (hereinafter, referred to as manualmode) by a function switch 9, the user can edit pit art data Dp byoperating the rotary switch 11 or the keyboard 22.

Operation in the external data recording mode will be described firstwith reference to flowcharts in FIGS. 5 and 6. In operation describedhere as a typical case, the user loads a CD-R as a disk DSC in thisdigital audio system 1, connects a CD player as external equipment tothe digital input terminal 13 and records (copies) reproduced data of aCD-DA reproduced by the CD player on the CD-R as a disk DSC.

In FIG. 5, when the user loads a disk DSC, the TOC data Dt2, which istable of contents information, is reproduced from the disk DSC andstored in a first memory (not shown) in the system controller 21 (stepS100).

Subsequently, the type of the loaded disk is judged based on the TOCdata Dt2 (step S102).

Subsequently, whether a recordable disk is loaded is judged (step S104).Here, if a disk exclusively used for reproduction such as a CD-ROM orthe like is loaded, record prohibition processing such as displaying amessage in the display unit 4 to the effect that data cannot be recordedis performed (step S106). Then, the processing is forcibly terminated.

On the other hand, when the disk DSC is a CD-R, it is determined that arecordable disk is loaded and the processing proceeds to step S108.

In step S108, whether a recording start switch 10 is turned on is judgedand the processing remains in a standby state until the switch is turnedon. In this standby state, the user starts reproduction by the CDplayer, which is external equipment. When the user further turns on therecording start switch 10, data reproduced from the CD player isinputted as input data D1.

Subsequently, the encoder 26 acquires TOC data Dt1, which is table ofcontents information included in the input data D1. This data is storedin a second memory (not shown) in the system controller 21 (step S110).

Subsequently, the pickup 28 is moved to a recording start address on adisk DSC. If data is already recorded in the disk DSC, a new tracknumber TRNO is obtained by adding 1 to the track number TRNO assigned tothe data (step S112).

Subsequently, the encoder 26 encodes the input data D1 and startsrecording the data by the pickup 28 by using the new track number TRNOas a first track number (step S114).

Subsequently, whether the track number assigned to the data D1 from theCD player, which is a copy source, is changed is judged (step S116). Ifthe track number is not changed, data recording in step S114 iscontinued.

On the other hand, if it is determined in step S116 that the tracknumber assigned to the data D1 is changed, the processing proceeds tostep S118 and whether supply of the data D1 from the CD player isfinished is judged. Here, if the supply of the data D1 is not finished,it is determined that data D1 of the next track number is supplied. Instep S112, the next track number is set and recording of the data D1 iscontinued (step S114).

When all the data D1 from the CD player is recorded, the processingproceeds to step S120 and finalization processing is performed. Thetable of contents information about the data D1 recorded so far iswritten in a read-in area of the disk DSC together with TOC data Dt2.After data is further recorded in a read-out area, the processing ishalted (step S122) and then proceeds to step S200 in FIG. 6.

In step S200 in FIG. 6, whether the user turns on a pit art recordingstart switch among the function switches 9 during the halt state isjudged. Here, if the pit art recording start switch is not turned onwithin a prescribed time, the processing proceeds to step S202 and pitart recording prohibition processing is performed. Then a series of datarecording processing is terminated without carrying out pit artrecording.

On the other hand, when the pit art recording start switch is turned on,the processing is halted (step S204) and then proceeds to step S206.

In step S206, the first address ADRS of an unrecorded area remaining inthe disk DSC is detected from the TOC data Dt2 acquired in step S100 andthe table of contents information data written in step S120. Further, aterminal end address ADRE of the unrecorded area is detected based onthe maximum read-out start position information (position informationindicating the latest address among position information standardized asread-out recording start address) recorded as ATIP information in awobbled portion of the read-in area. Then, these address data ADRS andADRE are supplied to the pit art data editing partXX 41 shown in FIG. 3with data D7 for editing instruction.

Furthermore, the pit art data editing partXX 41 calculates the shape ofthe unrecorded area based on the address data ADRS and ADRE. That is, asshown in FIG. 7, the width W of the unrecorded area in the radiusdirection of the disk DSC is calculated and the shape of the unrecordedarea in an annular shape matching the width W is obtained.

Subsequently, in step S208, character information data D6 (data such asalbum titles, names of music pieces, artist names and the like)conforming to the CD-TEXT standard included in the TOC data Dt1 storedin the second memory is supplied to the character data decoding partXX40 shown in FIG. 4.

Subsequently, in step S210, the character data decoding partXX 40retrieves standard character data Dc corresponding to the characterinformation data D6 and supplies the data to the pit art data editingpartXX 41. The pit art data editing partXX 41 converts the standardcharacter data Dc to bit map data Dbmp.

Subsequently, in step S212, the pit art data editing partXX 41 comparesthe size of the bit map data Dbmp and the shape of the unrecorded areaand automatically edits the resolution (dot density per unit area) andsize of the bit map data Dbmp so that the pit art does not overflow fromthe unrecorded area. Then, the edited bit map data Dbmp is stored in thebit art data memory 37.

Subsequently, in step S214, the bit map data Dbmp stored in the pit artdata memory 37 is supplied to the display unit 4 through themicrocomputer MPU. A display indicating how the pit art is formed in theunrecorded area of the disk DSC is presented. That is, a preview isdisplayed.

FIG. 8 shows an example of a preview display. For example, if thecharacter information data D6 is an album title “ABCDE”, the shapes ofthe disk DSC and the unrecorded area are displayed. Bit map data Dbmp ofthe edited “ABCDE” is further displayed in the display of the unrecordedarea.

In addition, a message for prompting an instruction about whether pitart recording of this bit map data Dbmp can be started, for example, “DOYOU WANT TO RECORD THE DISPLAYED IMAGE?” or the like is displayed.

Thus, the user can view in advance the size, layout and the like ofcharacters “ABCDE” to be recorded as a pit art.

Subsequently, when continuation of pit art recording is instructed bythe function switch 9 in response to this preview display in step S216,the processing proceeds to step S218. On the other hand, if terminationof pit art recording is instructed by the function switch 9, theprocessing proceeds to step S202 and pit art recording prohibitionprocessing is performed to terminate a series of data recordingprocessing. For example, if the user views the preview display anddetermines that the characters of “ABCDE” to be recorded as a pit artare too small, that the position of the pit art in the unrecorded areais not appropriate or the like, unnecessary pit art recording is notperformed by instructing to terminate the pit art recording.

If the pit art becomes too small because the shape of the unrecordedarea (particularly, width W of the unrecorded area) is small when thepit art data editing partXX 41 compares the shape of the unrecorded areaand the size of the bit map data Dbmp, the processing may automaticallyproceeds to step S202 so that pit art recording is not performed.

Subsequently, in step S218, after the pickup 28 is moved from the startaddress ADRS of the unrecorded area to a position a prescribed number oftracks N1 away (in this embodiment, N1=1000 tracks) outward in theradius direction, a portion of the prescribed number of tracks N2 (inthis embodiment N2=1000 tracks) outward in the radius direction fromthis moved position is irradiated with writing light having a prescribedpower to form an annular pit art. Consequently, the annular unrecordedportion of N1 tracks and the annular pit art of N2 tracks are arrangedas concentric circles outside the recorded area from the read-in area tothe start address ADRS in which data is already recorded. Therefore,this annular pit art can be seen as a border of the recorded area andthe pit art described later.

When the pit art data editing partXX 41 automatically edits theresolution (dot density per unit area) and the size of the bit map dataDbmp in step S212 as well, the bit map data Dbmp is automatically editedbased on the annular unrecorded portion of N1 tracks and the shape ofunrecorded area existent outside of the annular pit art portion of N2tracks in the radius direction.

Subsequently, in step S220, the pickup 28 is positioned at an addresslocated outside in the radius direction of the disk DSC of the portionwhere the annular pit art is formed. Further, in step S222, the firstone dot of the bit map data Dbmp is read from the pit art data memory 37and written in the unrecorded area of the disk DSC when supplied to thepickup 28 as pit art data Dp.

Subsequently, whether pit art recording is completed is judged in stepS224. If the recording is not completed, the processing goes back tostep S220 and the bit map data Dbmp of the next one dot is supplied tothe pickup 28 as pit art data Dp and recorded at the next address of theunrecorded area (step S222).

Then, when pit art recording is completed, the display unit 4 displays amessage to the effect that pit art recording is completed in step S226and then pit art recording is terminated.

When pit art recording is thus performed, as shown in FIG. 9, a pit artPA1 composed of annular pit strings indicating a border of the recordedarea and the unrecorded area and a character pit art PA2 such as “ABCDE”or the like are formed.

Then, the annular pit art PA1 and the character portion of the pit artPA2 are recorded as a multiplicity of pits in the recording layer of theCD-R and pits are not formed in the background portion. Since thereflectance of the portion where pits are formed is different from thatof the portion where pits are not formed, a pit art PA2 such as “ABCDE”is visible due to this difference in reflectance.

Thus, when a pit art is formed in the external data recording mode, theuser can readily identify or manage disks only by viewing the pit artPA2.

When information is hand-written in a conventional technique, there areproblems that labels become unclear or the appearance is deterioratedand the like. However, since the pit art is formed in the recordinglayer of the disk, clarity is maintained and there is not problem suchas deterioration of the appearance or the like.

The recorded area and the unrecorded area can be distinguished only byviewing the annular pit art PA1. Therefore, the user can judge that theunrecorded area where the pit art PA2 is formed can be touched by hand,but the recorded area where data is recorded should not be touched.

When data is reproduced, data of the pit art is not reproduced bymistake by detecting the annular pit art PA1 and finding presence of theunrecorded area where a pit art is formed.

Since the recording layer of the CD-R is formed with organic dye, a pitart can be formed clearly when a pit art is recorded. In particular,when a pit art is recorded in a CD-R having a recording layer formedwith cyanine or azo dye, a pit art with high contrast can be formed.

As described above, since a CD-R is loaded or unloaded in this digitalaudio system 1 with the recording layer side up and the label side down,the user can handle the CD-R while viewing the pit art. Therefore, theuser can readily manage or identify disks according to the pit art andthus convenience of a pit art can be more effectively provided. However,a CD-R may be loaded/unloaded with the recording layer side down and thelabel side up and a pit art may be recorded from the recording layerside facing downward.

In this external data recording mode, since the character informationdata in the table of contents information supplied from the CD player isautomatically recorded to the copy target disk as pit art data, a methodof easily recording a pit art can be provided to the user.

Although the case where a CD player is connected as external equipmenthas been described, when an MD player is connected, characterinformation data included in UTOC data can be recorded as pit art data.When a CS tuner or BS tuner is connected, character information receivedby the CS tuner or BS tuner can be recorded as pit art data.

In the external data recording mode described above, after finalizationprocessing is performed in step S120, processing for pit art recordingshown in FIG. 6 is performed. However, the processing for pit artrecording may be started without finalization processing as amodification.

However, in this case, in the step S120, when writing of the data D1 iscompleted, table of contents information assigned to data D1 is recordedas temporary TOC in a program management area (PMA) inside the read-inarea of the disk DSC. Then, processing for pit art recording shown inFIG. 6 is performed.

Furthermore, in processing for pit art editing and preview displaying insteps S206-S214, the start address ADRS of the unrecorded area isdetected based on the temporary TOC information. The position of a trackbeing relatively many tracks away from the start address ADRS outward inthe radius direction is assumed as the first position where a pit artcan be recorded. Pit art editing and preview displaying are carried outby assuming the unrecorded area further outward from the start positionin the radius direction as an area where a pit art can be recorded.

Furthermore, when the annular pit art PA1 and pit art PA2 are recordedin steps S218-S224 as well, these annular pit art PA1 and pit art PA2are recorded in the unrecorded area outside of a position being10,000-30,000 tracks away from the start address ADRS outward in theradius direction.

According to this modification, the unrecorded area of N1 tracks shownin FIG. 9 is secured for 10,000-30,000 tracks and so-called partial diskcan be created. Consequently, the user can additionally record data inthe unrecorded area secured for 10,000-30,000 tracks. Therefore, apartial disk which is more convenient and can be easily managed or thelike by the recorded pit art can be provided.

When the additionally recordable unrecorded area of 10,000-30,000 tracksis secured, the user may select the desired number of tracks in a rangeof this number of tracks or the user may specify the desired number oftracks without limitation of the number of tracks. Or, the user mayspecify the number of tracks as an amount converted to time to securethe specified unrecorded area as an additionally recordable area.

Operation in an internal data recording mode will be described belowwith reference to a flowchart in FIG. 10. In operation described here asa typical case, the user loads a finalized CD-R, that is, a CD-R inwhich TOC information is already recorded in the read-in area and datais recorded in the read-out area, in the digital audio system 1 and apit art is recorded in this CD-R.

In FIG. 10, when the user loads a finalized CD-R, TOC data Dt2, isreproduced from the loaded disk DSC and stored in the first memory (notshown) in the system controller 21 (step S300) and the processing ishalted (step S302).

In this halt state, when the user operates a prescribed operating switchamong the function switches 9 to select the internal data recordingmode, the processing proceeds to step S304. Based on the TOC data Dt2 inthe first memory, the type of the disk is judged.

Subsequently, whether a recordable disk is loaded is judged (step S306).Here, if a disk exclusively used for reproduction such as a CD-ROM orthe like is loaded, record prohibition processing such as displaying amessage in the display unit 4 to the effect that data cannot be recordedis performed (step S308). Then, the processing is forcibly terminated.On the other hand, when the disk DSC is a CD-R, it is determined that arecordable disk is loaded and the processing proceeds to step S310.

In step S310, a first address ADRS of an unrecorded area remaining inthe disk DSC is detected from the TOC data Dt2 in the first memory.Further, a terminal end address ADRE of the unrecorded area is detectedbased on the maximum read-out start position information (positioninformation indicating the latest address among position informationstandardized as read-out recording start address) recorded as ATIPinformation in a wobbled portion of the read-in area. Then, theseaddress data ADRS and ADRE are supplied to the pit art data editingpartXX 41 shown in FIG. 4 together with data D7 for edit instruction.

Furthermore, the pit art data editing partXX 41 calculates the shape ofthe unrecorded area based on the address data ADRS and ADRE. That is, asshown in FIG. 7, the width W of the unrecorded area in the disk DSCradius direction is calculated and the shape of the unrecorded area inan annular shape matching the width W is obtained. In this step S310 aswell as in step S206 in FIG. 6, the width W and shape of the unrecordedarea N1 tracks outward in the radius direction from the start addressADRS of the unrecorded area is calculated.

Subsequently, in step S312, character information data D6 (data such asalbum titles, names of music pieces, artist names and the like) includedin the TOC data Dt1 stored in the first memory is supplied to thecharacter data decoding partXX 40 shown in FIG. 4.

Subsequently, in step S314, the character data decoding partXX 40retrieves standard character data Dc corresponding to the characterinformation data D6 and supplies the data to the pit art data editingpartXX 41. The pit art data editing partXX 41 converts the standardcharacter data Dc to bit map data Dbmp.

Subsequently, in step S316, the pit art data editing partXX 41 comparesthe size of the bit map data Dbmp and the shape of the unrecorded areaand automatically edits the resolution (dot density per unit area) andsize of the bit map data Dbmp so that the pit art does not overflow fromthe unrecorded area. Then, the edited bit map data Dbmp is stored in thepit art data memory 37.

Subsequently, in step S318, the bit map data Dbmp stored in the pit artdata memory 37 is supplied to the display unit 4 through themicrocomputer MPU. A preview display indicating how the pit art isformed in the unrecorded area of the write-once type disk DSC ispresented.

For example, as in the case shown in FIG. 8, if the characterinformation data D6 is an album title “ABCDE”, the shapes of the diskDSC and the unrecorded area are displayed. Bit map data Dbmp of theedited “ABCDE” is further displayed in the display of the unrecordedarea. Based on this bit map data Dbmp, a message for prompting aninstruction about whether pit art recording can be started, for example,“DO YOU WANT TO RECORD THE DISPLAYED IMAGE?” or the like is displayed.

Consequently, the user can view in advance the size, layout and the likeof characters “ABCDE” to be recorded as a pit art.

Subsequently, when continuation of pit art recording is instructed bythe function switch 9 in response to this preview display in step S320,the processing proceeds to step S322. On the other hand, if aninstruction not to perform pit art recording is given by the functionswitch 9, the processing proceeds to step S308 and pit art recordingprohibition processing is performed to terminate a series of datarecording processing.

In step S322, the pickup 28 is moved from the start address ADRS of theunrecorded area to a position being N1 tracks away. A portion of N2tracks from this position is irradiated with writing light having aprescribed power. Consequently, an annular pit art PA1 indicating aborder of the unrecorded area and the recorded area is formed.

Subsequently, in step S324, the pickup 28 is positioned at an address ofthe portion where the annular pit art is formed, the address beingpositioned outside in the radius direction of the disk DSC. Further, instep S326, the first one dot of the bit map data Dbmp is read from thepit art data memory 37 and written in the unrecorded area of the diskDSC when supplied to the pickup 28 as pit art data Dp.

Subsequently, in step S328, whether pit art recording is completed isjudged. If the recording is not completed, the processing goes back tostep S324 and the bit map data Dbmp of the next one dot is supplied tothe pickup 28 as pit art data Dp and recorded at the next address of theunrecorded area (step S326).

Then, when writing of all bit map data Dbmp is completed, the displayunit 4 displays a message to the effect that pit art recording iscompleted in step S330 and then pit art recording is terminated.

When pit art recording is thus performed, as shown in FIG. 9, an annularpit art PA1 indicating a border of the recorded area and the unrecordedarea and a character pit art PA2 such as “ABCDE” or the like are formed.Since the reflectance of the portion where pits are formed is differentfrom that of the portion where pits are not formed, the user can easilyidentify or manage disks only by viewing the pit arts PA1 and PA2.

According to this internal data recording mode, table of contentinformation data already recorded in the CD-R can be automaticallyrecorded as pit art data. Consequently, benefits such as utilizing a pitart as if data were hand-written and so forth can be provided to a user.

The case where a pit art is recorded in a finalized CD-R in the internaldata recording mode has been described above. However, a pit art may berecorded in a partial disk.

In this case, a pit art can be recorded in a partial disk as well byprocessing temporary TOC information recorded in the PMA of the partialdisk as the TOC information recorded in the finalized CD-R.

Operation in a manual mode will be described below with reference to aflowchart in FIG. 11. In operation described here as a typical case, theuser loads a finalized CD-R in this digital audio system 1, then edits apit art and records the pit art in the loaded CD-R.

In FIG. 11, when the user loads the finalized CD-R, TOC data Dt2, whichis table of contents information, is reproduced from the loaded disk DSCand stored in the first memory in the system controller 21 and theprocessing is halted (step S400).

In this halt state, when the user operates a prescribed operating switchamong the function switches 9 to select the manual mode, the processingproceeds to steps S402-406.

In steps S402-406, desired characters, symbols, illustrations or thelike are inputted by the rotary switch 11 called as a jog dial or thekeyboard 22. Whether these characters or the like are selected isjudged. If not yet, the processing remains in a standby state until theabove input and select operation are carried out (step S402).

Here, if the above characters or the like are inputted, the inputteddata such as characters or the like is stored temporarily in aprescribed buffer register and these characters or the like are blinkedin the display unit 4. When select operation is performed, the data suchas characters or the like in the buffer register is stored in a buffermemory and settled and the aforementioned blinking display is changed toa stationary display (display which does not blink) to indicate that theinputted characters or the like are settled (step S404).

More specifically, for example, when the user appropriately rotates therotary switch 11 to input a character string “ABCDE” and an operatingswitch for selection (hereinafter, referred to as enter key) is operatedeach time each character is inputted, that is, (A) _ (enter) _ (B) _(enter) _ (C) _ (enter) _ (D) _ (enter) _ (E) _ (enter) are pressed, thecharacter string “ABCDE” can be specified and the character string isdisplayed in the inputted order as shown in FIG. 12.

When the keyboard 22 is operated, the character string “ABCDE” isinputted by using keys provided on the keyboard 22 and each time eachcharacter is inputted, the “return key” is pressed to specify thecharacter string “ABCDE”.

Thus, when the user inputs the desired character string and operates aprescribed operating switch among the function switches 9 to instructfinal settlement of the character string as a pit art, the processing ishalted (step S408) and then proceeds to step S410. When the useroperates a keyboard 22 and the aforementioned “return key” provided onthe keyboard 22 is operated again, the processing proceeds to step S408and then to step S410.

In step S410, the type of the disk is judged based on the TOC data Dt2in the first memory.

Subsequently, whether a recordable disk is loaded is judged (step S412).Here, if a disk exclusively used for reproduction such as a CD-ROM orthe like is loaded, record prohibition processing such as displaying amessage in the display unit 4 to the effect that data cannot be recordedis performed (step S414). Then, the manual mode is forcibly terminated.On the other hand, when the disk DSC is a write-once type disk, it isdetermined that a recordable disk is loaded and the processing proceedsto step S416.

In step S416, a first address ADRS of an unrecorded area remaining inthe write-once disk DSC is detected from the TOC data Dt2 in the firstmemory. Further, a terminal end address ADRE of the unrecorded area isdetected based on the maximum read-out start position information(position information indicating the latest address among positioninformation standardized as read-out recording start address) recordedas ATIP information in a wobbled portion of the read-in area. Then,these address data ADRS and ADRE are supplied to the pit art dataediting partXX 41 shown in FIG. 4 together with data D7 for editinginstruction.

Furthermore, the pit art data editing partXX 41 calculates the shape ofthe unrecorded area based on the address data ADRS and ADRE. That is, asshown in FIG. 7, the width W of the unrecorded area in the radiusdirection of the disk DSC is calculated and the shape of the unrecordedarea in an annular shape matching the width W is obtained.

In this step S416 as well as in step S206 in FIG. 6, the width W andshape of the unrecorded area N1 tracks outward in the radius directionfrom the start address ADRS of the unrecorded area is calculated.

Subsequently, in step S418, data D6 such as a character string or thelike (data such as character string or the like selected by the user)stored in the buffer memory is supplied to a character data decodingpartXX 40 shown in FIG. 4.

Subsequently, in step S420, the character data decoding partXX 40retrieves standard character data Dc corresponding to the data D6 andsupplies the data to the pit art data editing partXX 41. The pit artdata editing partXX 41 converts the standard character data Dc to bitmap data Dbmp.

Subsequently, in step S422, the pit art data editing partXX 41 comparesthe size of the bit map data Dbmp and the shape of the unrecorded areaand edits the resolution (dot density per unit area) and size of the bitmap data Dbmp so that the pit art does not overflow from the unrecordedarea. Then, the edited bit map data Dbmp is stored in the pit art datamemory 37.

Subsequently, in step S424, the bit map data Dbmp stored in the pit artdata memory 37 is supplied to the display unit 4 through themicrocomputer MPU. A preview display indicating how the pit art isformed in the unrecorded area of the write-once type disk DSC ispresented.

For example, as shown in FIG. 13, if the data D6 is a character string“ABCDE”, the shapes of the disk DSC and the unrecorded area aredisplayed. Bit map data Dbmp of the edited “ABCDE” is further displayedin the display of the unrecorded area. Based on this bit map data Dbmp,a message for prompting an instruction about whether pit art recordingcan be started, for example, “DO YOU WANT TO RECORD THE DISPLAYEDIMAGE?” or the like is displayed.

Consequently, the user can view in advance the size, layout and the likeof characters “ABCDE” to be recorded as a pit art.

Subsequently, when continuation of pit art recording is instructed bythe function switch 9 or the keyboard 22 in response to this previewdisplay in step S426, the processing proceeds to step S428. On the otherhand, if an instruction not to perform pit art recording is given by thefunction switch 9 or the keyboard 22, the processing proceeds step S414and pit art recording prohibition processing is performed to terminate aseries of data recording processing.

Subsequently, in step S428, the pickup 28 is moved from the startaddress ADRS of the unrecorded area to a position being N1 tracks awayoutward in the radius direction. Then, a portion of N2 tracks isirradiated with writing light having a prescribed power. Consequently,an annular pit art PA1 indicating a border of the unrecorded area andthe recorded area is formed.

Subsequently, in step S430, the pickup 28 is positioned at an address ofthe portion where the annular pit art PA1 is formed, the address beingpositioned outside in the radius direction of the disk DSC. Further, instep S432, the first one dot of the bit map data Dbmp is read from thepit art data memory 36 and written in the unrecorded area of the diskDSC when supplied to the pickup 28 as pit art data Dp.

Subsequently, in step S434, whether all the bit map data Dbmp is writtenin the unrecorded area is judged. If not, the processing goes back tostep S430 and the bit map data Dbmp of the next one dot is supplied tothe pickup 28 as pit art data Dp and recorded at the next address of theunrecorded area (step S432).

Then, when writing of all bit map data Dbmp is completed, the displayunit 4 displays a message to the effect that pit art recording iscompleted in step S436 and then pit art recording is terminated.

When pit art recording is thus performed, as shown in FIG. 9, an annularpit art PA1 indicating a border of the recorded area and the unrecordedarea and a character pit art PA2 such as “ABCDE” or the like are formed.Since the reflectance of the portion where pits are formed is differentfrom that of the portion where pits are not formed, the user can easilyidentify or manage disks only by viewing the pit arts PA1 and PA2.

According to this manual mode, the user can record a desired title orthe like as pit art data. Therefore, benefits such as utilizing a pitart as if data were hand-written and so forth can be provided to a user.

Thus, since a visible pit art is recorded in a recordable disk accordingto the digital audio system of this embodiment, the user can manage oridentify a plurality of disks by viewing the patterns.

The case where a pit art edited by the user is recorded in a finalizedCD-R in the manual mode has been described above. However, a pit artedited by the user can be recorded in a partial disk as well. In thiscase, the pit art can be recorded in a partial disk by processingtemporary TOC information recorded in the PMA area of the partial diskas the TOC information recorded in the finalized CD-R.

In this embodiment described above, the case where a pit art is recordedin a CD-R has been described. However, a pit art can be recorded inoptical recording media in which data can be written, such as CD-RW,DVD-R, DVD-RW and the like as well.

According to the digital audio system of this embodiment, when a disk onboth sides of which data can be recorded such as a DVD-R or the like isused, one recordable side can be exclusively used for recording a pitart and the other side can be used as a side for recording usual data.

When a disk both sides of which are recordable such as a DVD-R or thelike is used, part of one recordable side can be used as an area forrecording a pit art and part of the other recordable side can also beused as an area for recording a pit art so that pit arts can be formedon both sides and usual data can also be recorded on both sides.

As shown in FIG. 8, the case where a pit art such as a character stringor the like is arranged in a line has been described. However, acharacter string or the like can be arranged in a circular arc to form apit art matching the shape of the circular disk. A editing functioncapable of editing pit map data in a various manner may be provided byassuming the whole unrecorded area the same as the conventional labelside.

In the above embodiments, the case where a pit art is recorded bywriting light used in normal data recording has been described. However,since the spot diameter of the writing light irradiated on the recordinglayer of a disk is small, a problem is expected that a long time isrequired to form a visible-pit art. Therefore, when a pit art isrecorded, an object lens provided on the pickup 28 may be adjusted toirradiate with writing light having a larger spot diameter.Alternatively, a pickup exclusively used for pit art recording byirradiating with writing light having a large spot diameter may beprovided.

In the above embodiments, a pit art is automatically recorded in theexternal data recording mode and the internal data recording mode.However, the user may edit pit art data by manual operation in theseexternal data recording mode and internal data recording mode as well.

In steps S206 in FIG. 6, S310 in FIG. 10 and S416 in FIG. 11, the shapeof the unrecorded area is detected based on the TOC information ortemporary TOC information and ATIP information. As another modification,the shape of the unrecorded area may be detected by moving the pickup inthe radius direction of the disk DSC and based on the difference in thequantity of returning light (reflected light) from the recorded area andunrecorded area obtained upon this movement.

The shape of the unrecorded area may be detected or judged not based onthe difference in the reflected light quantity from the recorded areaand the unrecorded area, but by comparing the reflected light quantityfrom the recorded area or that from the unrecorded area with aprescribed threshold value or the like.

In this embodiment, both the writing for forming an image pattern (pitart) and normal information writing are performed by one pickup 28 aswriting means. However, a pickup for forming an image pattern (pit art)as well as a pickup for normal information writing may be provided.

In this embodiment, the case where so-called bit map data is generatedand a pit art is recorded in the recording layer of an optical recordingmedium by light beam modulated based on the bit map data has beendescribed. However, a pit art may be recorded not only based on theso-called bit map data but also based on data in other data formats.

A pit art is recorded not only depending on presence of pits, but thesize of pits may be adjusted or the interval between pits may beadjusted to record a pit art so that a pit art visually having aplurality of gradations can be recorded. Consequently, a pit art whichcan express shades, that is, a pit art having an expressive ability canbe formed.

The case where an annular pit art PA1 is formed between an area wherenormal information is recorded (recorded area) and an area where a pitart is to be recorded (unrecorded area) has been described. However, thepresent invention is not limited to this, but the pit art PA1 does nothave to be recorded. The user may select whether this annular pit artPA1 is recorded.

In the above embodiments, a digital audio system constituted by hardwarehas been described. However, the present invention is not limited tothis. The pit art recording function equivalent to this digital audiosystem may be achieved by a computer program.

For example, a recordable player (for example, a recordable CD player,DVD player or the like) which can record and reproduce data by using arecordable optical recording medium is mounted on a personal computer orthe like. A computer program having the aforementioned pit art recordingfunction is installed in the personal computer or the like and thecomputer program is executed by the personal computer so that a pit artis formed on an optical recording medium loaded in the recordableplayer.

According to this constitution, not only the users of the digital audiosystem, but convenience of pit art recording can be provided to manyother users.

When a computer program having the pit art recording function isinstalled in a personal computer or the like, an optical recordingmedium in which the computer program is recorded may be provided andinstalled by using a CD player or DVD player mounted on the personalcomputer or the like. Alternatively, the personal computer or the likemay be connected to a network such as the Internet or the like(including connection by telephone line, cable such as LAN or the likeor radio) and the computer program is transmitted (downloaded) via thenetwork so as to be set up in the personal computer or the like.

As described above, according to the information recording system andinformation recording method of the present invention, a recording layerformed in an optical recording medium is irradiated with light andchanges in optical characteristics of the portion irradiated with lightand the portion not irradiated with light in the recording layer aregenerated to form a visible image pattern. Therefore, a plurality ofoptical recording media can be managed or identified by viewing theformed image pattern.

1-14. (canceled) 15: An information writing apparatus for writinginformation on a write-once disk or a rewritable disk, comprising: adriver for driving said disk; and a writing component for writing avisible image pattern by irradiation of a light beam onto said disk toform pits on said disk, wherein said writing component performs writingof said visible image pattern while adjusting an interval between saidpits. 16: An information writing apparatus for writing information on awrite-once disk or a rewritable disk, comprising: a driver for drivingsaid disk; and a writing component for writing a visible image patternby irradiation of a light beam onto said disk to form pits on said disk,wherein said writing component performs writing of said visible imagepattern while adjusting a size of said pits. 17: An information writingapparatus as claimed in claim 15, wherein said writing component writesa visible image pattern having a gradation as said visible image patternby adjusting said interval between said pits. 18: An information writingapparatus as claimed in claim 16, wherein said writing component writesa visible image pattern having a gradation as said visible image patternby adjusting a size of each of said pits. 19: An information writingapparatus as claimed in claim 15, wherein said writing componentperforms the writing of said visible image pattern while also adjustinga size of said pits. 20: An information writing apparatus as claimed inclaim 15, wherein said writing component also performs writing of dataother than said visible image pattern. 21: An information writingapparatus as claimed in claim 20, wherein said data other than saidvisible image pattern is data representing music or images. 22: Aninformation writing apparatus as claimed in claim 20, wherein saidwriting component is commonly used to write said visible image patternand to record said data other than said visible image pattern. 23: Aninformation writing apparatus as claimed in claim 20, wherein saidwriting component has a semiconductor laser source, and saidsemiconductor laser source projects a reading light beam for readingsaid data other than said visible image pattern onto said disk, andprojects a writing light beam for writing said visible image patternonto said disk. 24: An information writing apparatus as claimed in claim20, wherein said visible image pattern is written on one surface of saiddisk, and said data other than said visible image pattern is recorded onthe other surface of said disk. 25: An information writing apparatus asclaimed in claim 16, wherein said writing component also performswriting of data other than said visible image pattern. 26: Aninformation writing apparatus as claimed in claim 25, wherein said dataother than said visible image pattern is data representing music orimages. 27: An information writing apparatus as claimed in claim 25,wherein said writing component is commonly used to write said visibleimage pattern and to record said data other than said visible imagepattern. 28: An information writing apparatus as claimed in claim 25,wherein said writing component has a semiconductor laser source, andsaid semiconductor laser source projects a reading light beam forreading said data other than said visible image pattern onto said disk,and projects a writing light beam for writing said visible image patternonto said disk. 29: An information writing apparatus as claimed in claim25, wherein said visible image pattern is written on one surface of saiddisk, and said data other than said visible image pattern is recorded onthe other surface of said disk. 30: An information writing method forwriting information on a write-once disk or a rewritable disk,comprising: a writing step for writing a visible image pattern byirradiation of a light beam on said disk to form pits on said disk,wherein in said writing step said visible image pattern is written whileadjusting an interval between said pits. 31: An information writingmethod for writing information on a write-once disk or a rewritabledisk, comprising: a writing step for writing a visible image pattern byirradiation of a light beam on said disk to form pits on said disk,wherein in said writing step said visible image pattern is written whileadjusting a size of said pits. 32: An information writing method asclaimed in claim 30, wherein in said writing step a visible imagepattern having a gradation is written as said visible image pattern byadjusting said interval between said pits. 33: An information writingmethod as claimed in claim 31, wherein in said writing step a visibleimage pattern having a gradation is written as said visible imagepattern by adjusting a size of each of said pits. 34: An informationwriting method as claimed in claim 30, wherein in said writing step thewriting of said visible image pattern is performed while also adjustinga size of said pits.